Proper design of exhaust systems in marine high-power turbocharged diesel engines can contribute to improve the low-speed performance of these engines and make the working conditions of the cylinders more uniform.Here...Proper design of exhaust systems in marine high-power turbocharged diesel engines can contribute to improve the low-speed performance of these engines and make the working conditions of the cylinders more uniform.Here a high-power marine 16-cylinder V-type turbocharged diesel engine is simulated using the GT-Power software.The results reveal the differences induced by different exhaust system structures,such as an 8-cylinder-inpipe exhaust system with single/double superchargers and a 4-cylinder-in-pipe exhaust system with a single supercharger.After a comparative analysis,the 8-cylinder type with double superchargers is determined to be the optimal solution,and the structure of the exhaust system is further optimized.The simulations show that the optimized maximum exhaust temperature difference among cylinders is reduced by 66%.Finally,the simulation results and the optimized performance of the designed exhaust system are verified through experiments.展开更多
Power deterioration is a major problem for diesel engines operating at high altitudes.This problem stems from the limited availability of turbocharger energy,which is not enough to increase the boost pressure to the r...Power deterioration is a major problem for diesel engines operating at high altitudes.This problem stems from the limited availability of turbocharger energy,which is not enough to increase the boost pressure to the required level.In this study,a control strategy is introduced in order to achieve engine power recovery at different altitudes.It is shown that as the altitude increases from 0 to 4500 m,the required boost pressure ratio increases from 2.4 to 4.3.The needed turbocharger energy should be increased accordingly by 240%,and the TCC(turbine characterization coefficient)should be adjusted within wide ranges.A 12%decrease in the TCC can lead to a rise of the intake air pressure,which can compensate the pressure decrease due to a 1000 m altitude increase.The fluctuation range of boost pressure was within 14.5 kPa for variations in altitude from 0 to 4500 m.展开更多
Purpose： This study aims to establish a new framework for evaluating science and technology （S＆T） competitiveness that is appropriate to meet the needs of provincial academies of sciences （PASs） in China.Design/...Purpose： This study aims to establish a new framework for evaluating science and technology （S＆T） competitiveness that is appropriate to meet the needs of provincial academies of sciences （PASs） in China.Design/methodology/approaches： An evaluation index, including such assessing indicators as research strength, research impact, research development and trends, and regional contributions, is developed for China＇s PASs. Taking the Jiangxi Academy of Sciences （JXAS） as an example, we first explain how to apply this framework to analyze the strengths and weaknesses of PASs in China. Then, we compare the results of all 17 PASs in order to get a comprehensive understanding of their competitiveness.Findings： Our results show the development path, current status, innovation advantages, and weaknesses of JXAS very clearly. Based on our comparative analysis, we ranked the 17 PASs from the perspective of different dimensions, by which their competitiveness strengths and weaknesses can be highlighted for improvement.Research limitations： In this analysis, we did not take S＆T policies, S＆T systems, or historical factors into consideration. Thus, we may have ignored the influence of the soft individual differences of different PASs in China..Practical implications： The evaluation index developed in this paper provides a useful insight into an analytical method that can be used by PASs or other provincial research institutions （PRIs） to assess their competitiveness.Originality/value： Compared with existing evaluation frameworks, our method has two main characteristics： First, we added three new dimensions, including the PASs＇ applicable research outputs, regional contributions, and comparative advantages; second, we conducted a comparative analysis of local research institutes in their different advantaged industrial areas, which makes our analytical method more comprehensive for local research institutions.展开更多
The COVID-19 pandemic has emerged as a global health emergency due to its association with severe pneumonia and relative high mortality.However,the molecular characteristics and pathological features underlying COVID-...The COVID-19 pandemic has emerged as a global health emergency due to its association with severe pneumonia and relative high mortality.However,the molecular characteristics and pathological features underlying COVID-19 pneumonia remain largely unknown.To characterize molecular mechanisms underlying COVID-19 pathogenesis in the lung tissue using a proteomic approach,fresh lung tissues were obtained from newly deceased patients with COVID-19 pneumonia.After virus inactivation,a quantitative proteomic approach combined with bioinformatics analysis was used to detect proteomic changes in the SARS-CoV-2-infected lung tissues.We identified significant differentially expressed proteins involved in a variety of fundamental biological processes including cellular metabolism,blood coagulation,immune response,angiogenesis,and cell microenvironment regulation.Several inflammatory factors were upregulated,which was possibly caused by the activation of NF-κB signaling.Extensive dysregulation of the lung proteome in response to SARS-CoV-2 infection was discovered.Our results systematically outlined the molecular pathological features in terms of the lung response to SARS-CoV-2 infection,and provided the scientific basis for the therapeutic target that is urgently needed to control the COVID-19 pandemic.展开更多
Severe neurological symptoms are associated with Coronavirus disease 2019(COVID-19).However,the morphologic features,pathological nature and their potential mechanisms in patient brains have not been revealed despite ...Severe neurological symptoms are associated with Coronavirus disease 2019(COVID-19).However,the morphologic features,pathological nature and their potential mechanisms in patient brains have not been revealed despite evidence of neurotropic infection.In this study,neuropathological damages and infiltrating inflammatory cells were quantitatively evaluated by immunohistochemical staining,ultrastructural examination under electron microscopy,and an image threshold method,in postmortem brains from nine critically ill COVID-19 patients and nine age-matched cadavers of healthy individuals.Differentially expressed proteins were identified by quantitative proteomic assays.Histopathological findings included neurophagocytosis,microglia nodules,satellite phenomena,extensive edema,focal hemorrhage,and infarction,as well as infiltrating mononuclear cells.Immunostaining of COVID-19 brains revealed extensive activation of both microglia and astrocytes,severe damage of the blood-brain barrier(BBB)and various degrees of perivascular infiltration by predominantly CD14+/CD16+/CD141+/CCR7+/CD11c+monocytes and occasionally CD4+/CD8+T lymphocytes.Quantitative proteomic assays combined with bioinformatics analysis identified upregulated proteins predominantly involved in immune responses,autophagy and cellular metabolism in COVID-19 patient brains compared with control brains.Proteins involved in brain development,neuroprotection,and extracellular matrix proteins of the basement membrane were downregulated,potentially caused by the activation of transforming growth factorβreceptor and vascular endothelial growth factor signaling pathways.Thus,our results define histopathological and molecular profiles of COVID-19-associated monocytic encephalitis(CAME)and suggest potential therapeutic targets.展开更多
Dear editor,Mycosis fungoides(MF),the most common subtype of cutaneous T cell lymphoma,is a rare disease[1,2].Patients with early-stageMF have a 5-year overall survival between 88%and 100%[3].In patients with advanced...Dear editor,Mycosis fungoides(MF),the most common subtype of cutaneous T cell lymphoma,is a rare disease[1,2].Patients with early-stageMF have a 5-year overall survival between 88%and 100%[3].In patients with advanced MF,the skin may present with tumors and erythroderma,and the median survival of patients with lymph node and visceral metastasis is 13 months[4].Therefore,it is important to achieve an early diagnosis to improve prognosis[5].展开更多
Dear Editor,Almost one-half of COVID-19 patients have symptoms of liver injury.However,the molecular characteristics in the COVID-19 liver remain unknown.Therefore,the need for long-term medication for recovery make i...Dear Editor,Almost one-half of COVID-19 patients have symptoms of liver injury.However,the molecular characteristics in the COVID-19 liver remain unknown.Therefore,the need for long-term medication for recovery make it imperative to study the infectivity and pathogenicity of SARS-CoV-2 in the liver.Here,we have identifed signifcant proteomic changes for the first time in the liver of COVID-19 patients.We detected differential expression levels of several proteins that mediate characteristic cellular host responses elicited by SARS-CoV-2 infection in the liver.展开更多
Dear Editor,The early diagnosis and prognosis of COVID-19 remain major challenges.At present,there are few studies focusing on the changes of sera proteome betAA/een active and recovered COVID-19 patients,and almost n...Dear Editor,The early diagnosis and prognosis of COVID-19 remain major challenges.At present,there are few studies focusing on the changes of sera proteome betAA/een active and recovered COVID-19 patients,and almost no biomarkers in sera are used to predict the function disorder of the injured tissues and organs in COVID-19 patients.In this study,we applied sera proteomics in the active and recovered COVID-19 patients,as well as healthy volunteers,combining with pathological staining of the patients'tissues to identify the potential prognosis biomarkers that can reflect specific organ damage.展开更多
基金the High-Tech Ship Scientific Research Project[MC-201501-D01-01].
文摘Proper design of exhaust systems in marine high-power turbocharged diesel engines can contribute to improve the low-speed performance of these engines and make the working conditions of the cylinders more uniform.Here a high-power marine 16-cylinder V-type turbocharged diesel engine is simulated using the GT-Power software.The results reveal the differences induced by different exhaust system structures,such as an 8-cylinder-inpipe exhaust system with single/double superchargers and a 4-cylinder-in-pipe exhaust system with a single supercharger.After a comparative analysis,the 8-cylinder type with double superchargers is determined to be the optimal solution,and the structure of the exhaust system is further optimized.The simulations show that the optimized maximum exhaust temperature difference among cylinders is reduced by 66%.Finally,the simulation results and the optimized performance of the designed exhaust system are verified through experiments.
基金funded by the National Natural Science Foundation of China[Grant Nos.51576129 and 12102298]the China Postdoctoral Science Foundation[Grant No.2021M702443]the State Key Laboratory of Engines(Tianjin University)[Grant No.K2022-09].
文摘Power deterioration is a major problem for diesel engines operating at high altitudes.This problem stems from the limited availability of turbocharger energy,which is not enough to increase the boost pressure to the required level.In this study,a control strategy is introduced in order to achieve engine power recovery at different altitudes.It is shown that as the altitude increases from 0 to 4500 m,the required boost pressure ratio increases from 2.4 to 4.3.The needed turbocharger energy should be increased accordingly by 240%,and the TCC(turbine characterization coefficient)should be adjusted within wide ranges.A 12%decrease in the TCC can lead to a rise of the intake air pressure,which can compensate the pressure decrease due to a 1000 m altitude increase.The fluctuation range of boost pressure was within 14.5 kPa for variations in altitude from 0 to 4500 m.
基金supported by the National Science Library of the Chinese Academy of Sciences(Grant No.:Y130181001)
文摘Purpose： This study aims to establish a new framework for evaluating science and technology （S＆T） competitiveness that is appropriate to meet the needs of provincial academies of sciences （PASs） in China.Design/methodology/approaches： An evaluation index, including such assessing indicators as research strength, research impact, research development and trends, and regional contributions, is developed for China＇s PASs. Taking the Jiangxi Academy of Sciences （JXAS） as an example, we first explain how to apply this framework to analyze the strengths and weaknesses of PASs in China. Then, we compare the results of all 17 PASs in order to get a comprehensive understanding of their competitiveness.Findings： Our results show the development path, current status, innovation advantages, and weaknesses of JXAS very clearly. Based on our comparative analysis, we ranked the 17 PASs from the perspective of different dimensions, by which their competitiveness strengths and weaknesses can be highlighted for improvement.Research limitations： In this analysis, we did not take S＆T policies, S＆T systems, or historical factors into consideration. Thus, we may have ignored the influence of the soft individual differences of different PASs in China..Practical implications： The evaluation index developed in this paper provides a useful insight into an analytical method that can be used by PASs or other provincial research institutions （PRIs） to assess their competitiveness.Originality/value： Compared with existing evaluation frameworks, our method has two main characteristics： First, we added three new dimensions, including the PASs＇ applicable research outputs, regional contributions, and comparative advantages; second, we conducted a comparative analysis of local research institutes in their different advantaged industrial areas, which makes our analytical method more comprehensive for local research institutions.
基金supported by the National Science and Technology Major Projects(2018ZX09711003).
文摘The COVID-19 pandemic has emerged as a global health emergency due to its association with severe pneumonia and relative high mortality.However,the molecular characteristics and pathological features underlying COVID-19 pneumonia remain largely unknown.To characterize molecular mechanisms underlying COVID-19 pathogenesis in the lung tissue using a proteomic approach,fresh lung tissues were obtained from newly deceased patients with COVID-19 pneumonia.After virus inactivation,a quantitative proteomic approach combined with bioinformatics analysis was used to detect proteomic changes in the SARS-CoV-2-infected lung tissues.We identified significant differentially expressed proteins involved in a variety of fundamental biological processes including cellular metabolism,blood coagulation,immune response,angiogenesis,and cell microenvironment regulation.Several inflammatory factors were upregulated,which was possibly caused by the activation of NF-κB signaling.Extensive dysregulation of the lung proteome in response to SARS-CoV-2 infection was discovered.Our results systematically outlined the molecular pathological features in terms of the lung response to SARS-CoV-2 infection,and provided the scientific basis for the therapeutic target that is urgently needed to control the COVID-19 pandemic.
基金This study was supported by the Emergency COVID-19 Projects from Guangzhou Laboratory(EKPG21-32 to X.-W.B.)from Chongqing Science and Technology Commission(2020NCPZX01,cstc2020jscx-fyzx0229 to X.-W.B.).
文摘Severe neurological symptoms are associated with Coronavirus disease 2019(COVID-19).However,the morphologic features,pathological nature and their potential mechanisms in patient brains have not been revealed despite evidence of neurotropic infection.In this study,neuropathological damages and infiltrating inflammatory cells were quantitatively evaluated by immunohistochemical staining,ultrastructural examination under electron microscopy,and an image threshold method,in postmortem brains from nine critically ill COVID-19 patients and nine age-matched cadavers of healthy individuals.Differentially expressed proteins were identified by quantitative proteomic assays.Histopathological findings included neurophagocytosis,microglia nodules,satellite phenomena,extensive edema,focal hemorrhage,and infarction,as well as infiltrating mononuclear cells.Immunostaining of COVID-19 brains revealed extensive activation of both microglia and astrocytes,severe damage of the blood-brain barrier(BBB)and various degrees of perivascular infiltration by predominantly CD14+/CD16+/CD141+/CCR7+/CD11c+monocytes and occasionally CD4+/CD8+T lymphocytes.Quantitative proteomic assays combined with bioinformatics analysis identified upregulated proteins predominantly involved in immune responses,autophagy and cellular metabolism in COVID-19 patient brains compared with control brains.Proteins involved in brain development,neuroprotection,and extracellular matrix proteins of the basement membrane were downregulated,potentially caused by the activation of transforming growth factorβreceptor and vascular endothelial growth factor signaling pathways.Thus,our results define histopathological and molecular profiles of COVID-19-associated monocytic encephalitis(CAME)and suggest potential therapeutic targets.
基金This work was supported by the National Natural Science Foundation of China(No.82173449)the Beijing Nature Science Foundation(No.7182127),the Nonprofit Central Research Institute Fund of Chinese Academy of Medical Sciences(No.2019XK320024)+1 种基金the National Key Research and Development Program of China(No.2016YFC0901500)the Medical and Health Science and Technology Innovation Project of Chinese Academy of Medical Sciences(2019-I2M-1-001).
文摘Dear editor,Mycosis fungoides(MF),the most common subtype of cutaneous T cell lymphoma,is a rare disease[1,2].Patients with early-stageMF have a 5-year overall survival between 88%and 100%[3].In patients with advanced MF,the skin may present with tumors and erythroderma,and the median survival of patients with lymph node and visceral metastasis is 13 months[4].Therefore,it is important to achieve an early diagnosis to improve prognosis[5].
基金This work was supported by the National Science and Technology Major Projects(2018ZX09711003)National Key Research and Development Project(2020YFC0841700)Ministry of Science and Technology of P.R.China Plan(2020YFC0844700).
文摘Dear Editor,Almost one-half of COVID-19 patients have symptoms of liver injury.However,the molecular characteristics in the COVID-19 liver remain unknown.Therefore,the need for long-term medication for recovery make it imperative to study the infectivity and pathogenicity of SARS-CoV-2 in the liver.Here,we have identifed signifcant proteomic changes for the first time in the liver of COVID-19 patients.We detected differential expression levels of several proteins that mediate characteristic cellular host responses elicited by SARS-CoV-2 infection in the liver.
基金This work was supported by the National Science and Technology Major Project(2018ZX09711003)the CAMS Innovation Fund for Medical Sciences(CIFMS)(2020-I2M-CoV19-001).
文摘Dear Editor,The early diagnosis and prognosis of COVID-19 remain major challenges.At present,there are few studies focusing on the changes of sera proteome betAA/een active and recovered COVID-19 patients,and almost no biomarkers in sera are used to predict the function disorder of the injured tissues and organs in COVID-19 patients.In this study,we applied sera proteomics in the active and recovered COVID-19 patients,as well as healthy volunteers,combining with pathological staining of the patients'tissues to identify the potential prognosis biomarkers that can reflect specific organ damage.
